1. Technical Field
The present invention relates to a liquid ejection apparatus configured to eject liquid from ejection openings.
2. Description of the Related Art
There is conventionally known an ink-jet head configured to eject ink droplets from a multiplicity of ejection openings and configured to clean the ejection openings by driving a pump to force ink into head passages formed in the ink-jet head to discharge, from the ejection openings, air bubbles and high-viscosity ink existing in portions of the head passages near the ejection openings. In one technique, a three-way valve is closed to close a discharge passage, and then a pump is driven to apply a pressure to the ink in head passages for a predetermined length of time to discharge the ink from the ejection openings and thereby clean the ejection openings.